I. Field
The present disclosure relates generally to electronic circuits, and more specifically to transmitters for wireless communication.
II. Background
A wireless device may support communication with multiple wireless communication systems. These systems may utilize different modulation schemes such as Gaussian minimum shift keying (GMSK), 8-ary phase shift keying (8-PSK), quadrature phase shift keying (QPSK), quadrature amplitude modulation (QAM), etc. These systems may also have different chip rates and/or operate on different frequency bands.
A transmitter within the wireless device may be designed to support multiple modulation schemes, multiple chip rates, and/or multiple frequency bands. To transmit data to a given system, the transmitter may first digitally process the data to generate symbols. The transmitter may then convert the symbols to analog signals, filter and amplify the analog signals, and modulate local oscillator (LO) signals with the amplified analog signals to generate a modulated signal. The transmitter may further filter and power amplify the modulated signal to generate a radio frequency (RF) output signal, which may then be transmitted via a wireless channel.
The transmitter may use various circuit blocks such as filters, amplifiers, mixers, etc. to generate an RF output signal for a given modulation scheme on a given frequency band. These circuit blocks may be designed to achieve good performance for the modulation scheme and the frequency band. To support multiple systems and/or multiple frequency bands, the circuit blocks may be replicated for each combination of modulation scheme and frequency band supported by the wireless device. This replication of circuit blocks may increase cost and power consumption for the wireless device.
There is therefore a need in the art for transmitters that can efficiently support different modulation schemes and/or frequency bands.